Model 481 Miniature Single Element Pyroelectric IR Detector

Model 481 contains a single lithium
tantalate sensing element and a JFET
source follower sealed into a standard
TO-18 transistor package with an optical
filter.
A patented element mounting technique
is used to improve thermal time
constant and reduce effects of
microphony.
A source resistor is needed to set
the drain current and consequently the
operating parameters of the JFET. A
47k